Reconfigurable Optical Add Drop Multiplexers (ROADMs) have been developed as an integral part of optical communication networks employing wavelength division multiplexing (WDM). The ROADM allows for an all-optical form of communication traffic control by allowing certain wavelength channels to be added and dropped as needed. More recent advances in ROADM architectures include the Colorless, Directionless, Contentionless (CDC) ROADM and gridless and flexible grid ROADMs. Additionally, the number of degrees of a ROADM, i.e. the number of switching directions, has tended to increase over time.
However, advances in ROADM technologies tend to be accompanied by a corresponding increase in the number of optical interconnections within the ROADM. To manage this, designers tend to bundle interconnections by employing backplanes and multi-fiber cables, such as ribbon cables terminating in MTP/MPO (multi-fiber pus-on, multi-path push-on) connectors. Both of these factors lead to reliability concerns. With a larger number of interconnections, the probability of a fault and the difficulty of finding the fault both increase. Due to bundling, it becomes difficult or impossible to diagnose faults by replacing components, without the diagnostic procedure being service affecting. Such problems can also be found in other types of optical networking equipment.
Therefore there is a need for a method and apparatus for dynamic monitoring and calibration of nodes in an optical networking device that obviates or mitigates one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.